淡水资源保护与地下空间利用

本文阐述了保护淡水资源的重要意义和紧迫性,论述了开发利用地下空间调蓄淡水资源所发挥的巨大作用,介绍了人工调蓄水资源采用的主要地下工程形式。本文围绕淡水资源保护这一中心议题,阐明了地下空间利用具有多方面的广阔前景。

鹿角胶工艺改进与质量

影响鹿角胶质量的工艺因素有“受热时间长”、“温度过高”、“含无机盐过多”等。为提高鹿角胶质量,煎胶受热时间控制在24小时以内;采用密闭加压(0.5kg),煎煮18小时,温度在110℃;选用含无机盐类较低的深层地下水熬制,这样的鹿角胶质量较佳。

简讯

据介绍,济宁市地下水资源总量严重不足,城区深层地下水允许可开采量约为每日23万m3。而目前的实际开采量已达每日35万m3,其中集中供水取水量为每日12万m3,自备井开采量高达23万m3。地下水的严重超采,导致地下水源不能得到有效的涵养和补充,造成地下水位持续下降,水质加速恶化,严重威胁到了城市水环境安全。

Mechanism of gas-water flow at pore-level in aquifer gas storage

By means of the pore-level simulation, the characteristics of gas-water flow and gas-water distribution during the alternative displacement of gas and water were observed directly from etched-glass micromodel. The results show that gas-water distribution styles are divided into continuous phase type and separate phase type. The water lock exists in pore and throat during the process of gas-water displacement, and it reduces the gas flow-rate and has some effects on the recovery efficiency during the operation of gas storage. According to the experimental results of aquifer gas storage in X area, the differences in available extent among reservoirs are significant, and the availability of pore space is 33% 45%.

Interlayer interference mechanism of multi-seam drainage in a CBM well:An example from Zhucang syncline

Based on the characteristics of the strong volatility of physical property in vertical direction, high gas content, high resource abundance and large exploitation potentiality of coal reservoir in Bide-Santang basin of Zhina coal field, we study the generation mechanism of interlayer interference, propagation rules of reservoir pressure drop and influencing factors of gas productivity in CBM multi-seam drainage in the paper. On the basis of the actual production data of X-2 well of Zhucang syncline in Bide-Santang basin,by simulating the gas production process of a CBM well under the condition of multiple seam with COMET3 numerical simulation software, we analyze the influencing factors of gas productivity during the process of multi-seam drainage, and illuminate the interlayer interference mechanism of multiseam drainage. The results show that permeability, reservoir pressure gradient, critical desorption pressure and fluid supply capacity of stratum have great influence on gas productivity of multi-seam drainage while coal thickness has little influence on it. Permeability, reservoir pressure gradient and fluid supply capacity of stratum affect the propagation velocity of reservoir pressure drop and thereby affect the final gas productivity. Moreover, the influence of critical desorption pressure on gas productivity of multiseam drainage is reflected in the gas breakthrough time and effective desorption area.

Spatial distribution of Ice Shelf Water in front of the Amery Ice Shelf,Antarctica in summer

As a unique low-temperature water mass in Antarctic coastal region, the Ice Shelf Water (ISW) is an important component for the formation of the Antarctic Bottom Water (AABW). In this paper, we present a criterion for ISW identification based on freezing point at the sea surface, and we study spatial distribution of ISW in front of the Amery Ice Shelf (AIS) and its flow path in Prydz Bay by analyzing hydrographic data from Australian cruises in 2001 and 2002, as well as Chinese cruises in 2003, 2005, 2006, and 2008, all being made in the austral summer. The relatively cold and fresh ISW occurred as several discrete water blocks with cold cores in front of the AIS, within the depth range of 100?600 m, under the seasonal thermocline. ISW had obvious temporal and spatial variations and the spatial distribution pattern changed greatly after 2005. Most of ISW was concentrated west of 73°E during 2001 to 2003 and 2006, but it was widespread to east in 2005 and 2008. In all observation years, a small amount of cold ISW always occurs at the west end of the AIS front section, where the coldest ISW in the whole section also occurred in 2001, 2003 and 2006. Considering general cyclonic circulation pattern under the AIS, the ISW flowing out from west end of the AIS front might have experienced the longest cooling period under ice shelf, so it would have the lowest temperature. Analysis of data from meridian sections in Prydz Bay in 2003 implied that ISW in the west could spread north to the continental break along the east flank of the Fram Bank near 70.5°E, mix with the upwelling Circumpolar Deep Water and possibly contribute to the formation of AABW.

Clay mineral expansion of black cotton soil based on interlayer cation hydration

To analyze the water swelling characteristics of black cotton soil(BCS),X-ray fluorescence and X-ray diffraction characterizations were performed to investigate the chemical compositions and types of clay minerals in BCS.A montmorillonite crystal lattice was established to simulate the hydration of interlayer cations by applying the SPC/E potential energy model,universal force field,algorithm of charge balance,and periodic boundary.Results indicated that the main clay mineral found in the BCS was montmorillonite(32.6%)with small amounts of interstratified illite-montmorillonite(10.9%),illite(2.3%),and kaolinite(1.5%).The high expansive potential of BCS comes from the strong adsorption property of montmorillonite with a high content of magnesium and sodium ions to water molecules.The exchangeable cations of Na^(+)in BCS were only 3.73%,but they enhanced the adsorption capacity of clay to water molecules and accelerated the hydration of Mg^(2+)(47.1%)and Ca^(2+)(4.78%).The free swell index can be used as a classification index of the swelling potential of BCS.

Stress spatial evolution law and rockburst danger induced by coal mining in fault zone

In order to explore the influence of coal mining disturbance on the rockburst occurring in fault zone, this research constructed a mechanical model for the evolution of fault stress, and analyzed the influence of the ratio of horizontal stress to vertical stress on the stability of fault, and the spatial distribution of the stress in fault zone as well as its evolution rule. Furthermore, the rockburst danger at different spatial areas of fault zone was predicated. Results show that: when both sides of the working face are mined out, the fault zone in the working face presents greater horizontal and vertical stresses at its boundaries but exhibits smaller stresses in its middle section; however, the ratio of horizontal stress to vertical stress is found to be greater at middle section and smaller at boundaries. As the working face advances towards the fault, the horizontal and vertical stresses of the fault firstly increases and then decreases; conversely,the ratio of horizontal stress to vertical stress keeps decreasing all the time. Therefore, if the fault zones are closer to the goaf and the coal wall, the stress ratio will be smaller, and the fault slip will be more prone to occur, therefore rockburst danger will be greater. This research results provide guidance for the rockburst prevention and hazard control of the coal mining in fault zone.

Evaluation of Spatial and Vertical Variability of Nitrogen and Phosphorus in Sewage-Irrigated Soil in Tongliao, China

The reuse of wastewater for the irrigation of farmlands is gaining popularity, and the nutrient leaching associated with wastewater irrigation is becoming a matter of concern. The variability of nitrogen and phosphorus frac- tions in wastewater-irrigated soil was investigated in both horizontal and vertical directions in Kongjiaxiang, Tongliao, Inner Mongolia, China. The results showed that wastewater irrigation resulted in the concentrations of available N and P being 40.36% and 66.49% higher, respectively, than those with groundwater irrigation. Different forms of N and P exhibited significantly different distribution pattems. Higher concentrations of NO~ and total available N, as well as of those of Ca-P and total available P were observed near wastewater irrigation channels. Ca-P has a spatial distribu- tion pattern similar to that of available P. The concentrations of NO3 and NH4 were the highest in top soil and de- creased with depth. The complex interactions between nitrate leaching and nitrogen transformation processes （e.g., nitrification, denitrification, and mineralization） determined the vertical profile of NO3. The significant amount of NH~ loss inhibited its deep seepage. The Ca-bound compound contained more P than other inorganic fractions as a result of high Ca levels throughout the soil profile. The differences in the concentrations of Ca-bound P at different depths could be due to the upward flux or translocation of Ca from subsurface to surface soil and the sequestration of P.

Reduced Ammonia Release by Frequently Removal of Manure below Draining Floors in a Floor Housing System for Laying Hens

The hygienic threshold limit values for ammonia （25 ppm） for animal welfare but also for occupational safety and health is often exceeded in floor housing systems for laying hens with long time storage of manure in bins below draining floors. The major reason for high ammonia concentrations is the large amounts of stored and exposed manure. The possibility to reduce ammonia release by reducing the amount of stored manure in bins in floor housing systems for laying hens has therefore been investigated. Investigations were carried out in a climate chamber equipped with a floor housing system with a manure removal system with two parallel motor driven conveyors placed below an elevated draining floor. The conditions when manure is stored in bins below draining floors were simulated by storing manure on the conveyors for several days at constant ventilation rates and temperatures. The investigations clearly showed that storage of manure in the bin caused a rapid increase in ammonia concentrations. After about 7 days storage of manure in the bin the ammonia concentration exceeded the hygienic threshold limit values. It can be concluded that long time storage of manure in storage bins below draining floors should not be recommended. It was possible to maintain the ammonia concentration below the hygienic threshold limit values when manure was removed frequently with conveyors. Floor housing systems for laying hens with elevated draining floors should therefore be equipped with manure removal systems that enable frequent removal of manure in the bins.

Meteorological Data Generation for the Numerical Simulation of Stratified Flow in the Joumine Reservoir, Tunisia

Dynamic numerical simulation of water conditions is useful for reservoir management. In remote semi-arid areas, however, meteorological and hydrological time-series data needed for computation are not frequently measured and must be obtained using other information. This paper presents a case study of data generation for the computation of thermal conditions in the Joumine Reservoir, Tunisia. Data from the Wind Finder web site and daily sunshine duration at the nearest weather stations were utilized to generate cloud cover and solar radiation data based on meteorological correlations obtained in Japan, which is located at the same latitude as Tunisia. A time series of inflow water temperature was estimated from air temperature using a numerical filter expressed as a linear second-order differential equation. A numerical simulation using a vertical 2-D （two-dimensional） turbulent flow model for a stratified water body with generated data successfully reproduced seasonal thermal conditions in the reservoir, which were monitored using a thermistor chain.

The Continuum Analytical Method of Steel Frame- Reinforced Concrete Shear Wall Mixed Structure

The inter-story drift stiffness considered the semirigidity of beam and column joints connection, and P-Delta second order effect of steel frame parts in the mixed structure is presented in the paper. After considering on the influence of semirigidity between steel beams and steel columns, second order effect of beam-column members for steel frame and structural second order effect, the traditional continuum analytial method used in RC shear-frames wall structure is developed to steel frames-reinforced concrete shear wall mixed structure subject to horizontal load in this paper. A continuum approach, which is suitable for analyzing steel frames-reinforced concrete shear wall mixed structure subject to horizontal load, is presented. The method is relatively simple and more practical. It will be referred to structural design for steel frames-reinforced concrete shear wall mixed structure.

Clustered trajectories anonymity in wireless sensor networks

This paper proposes a clustered trajectories anonymity scheme （CTA） that enhances the kano nymity scheme to provide the intended level of source location privacy in mobile event monitoring when a global attacker is assumed. CTA applies isomorphic property of rotation to create traces of the fake sources distributions which are similar to those of the real sources. Thus anonymity of each trajectory and that of the clustered is achieved. In addition, location kdiversity is achieved by dis tributing fake sources around the base station. To reduce the time delay, tree rooted at the base sta tion is constructed to overlap part of the beacon interval of the nodes in the hierarchy. Both the ana lytical analysis and the simulation results prove that proved energy overhead and time delay. our scheme provides perfect anonymity with improved energy overhead and time delay.

试论盐渍化土地的综合利用

我国有四亿亩盐渍土,分布在东北、华北、西北和东南沿海。其所含盐份以食盐、芒硝及苏打等为主,这些盐渍土大部分都未垦用;已被垦用的,由于盐份未能根除,作物产量一般也不高。因此,如何充分利用盐渍土,将是当前很重要的问题。我国对盐渍土的改良工作,自从农业合作化后,已逐渐采用了冲洗排水的改良方法,代替了以前个体农民落后的挖沟、垫土、压硷等局部改良方法。可是,冲洗排水的方法也还存在如下一些问题。

The significance and variation characteristics of interlay water in smectite of hydrocarbon source rocks

To investigate variation characteristics of interlayer water bound up with organic matter in smectite, organo-clay complexes extracted from grinded source rock samples were determined using thermo-XRD, DTA and PY-GC. The dool diffraction peak of organo-clay complexes is postponed from 250 to 550℃ before reaching 1.00 nm and accompanied by exothermal peaks on DTA and organic matter with abundant C20-C30carbon detected by PY-GC, which is different from single smectite and indicates the existence of organic matter in the interlayer of smectite. Water desorption characteristics of organo-clay complexes are in consistent with smectite at 100 and 600℃, but different from smectite at 550℃ with an additional dehydration peak and a remaining d001 diffraction peak, suggesting the vcater removed at 550℃ is interlayer adsorption water rather than constituent water of clay minerals. Comparing the dehydration order and water loss, we conclude that part of interlayer water of smectite may act as the ＂bridge＂ that binds organic matter and smectite, which results in water-expelled lag beyond 250℃ and may provide a good medium for hydrocarbon migration and oil pool formation.

Identification of the Exchange Coefficient from Indirect Data for a Coupled Continuum Pipe-Flow Model

Calibration and identification of the exchange effect between the karst aquifers and the underlying conduit network are important issues in order to gain a better understanding of these hydraulic systems. Based on a coupled continuum pipe-flow(CCPF for short) model describing flows in karst aquifers, this paper is devoted to the identification of an exchange rate function, which models the hydraulic interaction between the fissured volume(matrix) and the conduit, from the Neumann boundary data, i.e., matrix/conduit seepage velocity. The authors formulate this parameter identification problem as a nonlinear operator equation and prove the compactness of the forward mapping. The stable approximate solution is obtained by two classic iterative regularization methods, namely,the Landweber iteration and Levenberg-Marquardt method. Numerical examples on noisefree and noisy data shed light on the appropriateness of the proposed approaches.

Alumina-coated Ag nanocrystal monolayers as surfaceenhanced Raman spectroscopy platforms for the direct spectroscopic detection of water splitting reaction intermediates

A novel Ag-alumina hybrid surface-enhanced Raman spectroscopy （SERS） platform has been designed for the spectroscopic detection of surface reactions in the steady state. Single crystalline and faceted silver （Ag） nanoparticles with strong light scattering were prepared in large quantity, which enables their reproducible self-assembly into large scale monolayers of Raman sensor arrays by the Langrnuir-Blodgett technique. The close packed sensor film contains high density of sub-nm gaps between sharp edges of Ag nanoparticles, which created large local electromagnetic fields that serve as ＂hot spots＂ for SERS enhancement. The SERS substrate was then coated with a thin layer of alumina by atomic layer deposition to prevent charge transfer between Ag and the reaction system. The photocatalytic water splitting reaction on a monolayer of anatase TiO2 nanoplates decorated with Pt co-catalyst nanoparticles was employed as a model reaction system. Reaction intermediates of water photooxidation were observed at the TiO2/solution interface under UV irradiation. The surface-enhanced Raman vibrations corresponding to peroxo, hydroperoxo and hydroxo surface intermediate species were observed on the TiO2 surface, suggesting that the photo-oxidation of water on these anatase TiO2 nanosheets may be initiated by a nucleophilic attack mechanism.